MedicineNet defines a lifestyle disease as "A disease associated with the way a person or group of people lives." Examples include heart disease, obesity, stroke and type 2 diabetes. Lifestyle diseases are often associated with a person's actions, such as overeating, drug abuse, alcoholism or smoking.
Lifestyle diseases occur everywhere in the world and not just in the United States. In fact, ABC News quotes the World Health Organization as saying, "Non-communicable diseases are now the leading cause of death around the world, with developing countries hit hardest." The WHO estimates that 63 percent of worldwide deaths are due to lifestyle diseases, using information from 2008. In addition, 80 percent of these deaths take place in low- to middle-income countries. Such lifestyle diseases lead to premature death, which then affects the economic development of these countries.
Some lifestyle diseases are co-morbid with other diseases. Diabetes and hypertension, both lifestyle diseases themselves, also contribute to the risks for heart disease. However, even though one attempts to avoid these risk factors, the Mayo Clinic points out that sometimes a small choice a person makes can impact such diseases. For example, a lack of hand washing or poor dental care increases one's risk for infections that contribute to heart disease.